The process of circuit board assembly involves several stepwise operations requiring repeated handling of each circuit board. The placement of components on the board can be done in assembly line fashion in the case of mass production, but there will still be some operations performed in a batch fashion such as testing. Each time the circuit boards are handled, the danger of damage to the board increases. This is due to the structural deficiencies of the board and to the delicacy of the circuit components. As circuit boards and the circuit elements they carry become smaller due to advances in technology, the assembled board becomes increasingly susceptible to damage.
Events which carry with them an increased possibility of damage include component insertion, packing and unpacking in preparation for transport, and physical manipulation for testing. Each time the circuit boards are placed near a surface having a different voltage potential, the danger of static discharge into the circuit elements on the board is increased. High voltage, low current potentials of thousands of volts are present in static discharges, and can totally destroy semiconductor circuit elements.
Adequate structural support must also be provided whenever the board is physically manipulated. When circuit elements are added to the board on one side, the reverse side may be damaged by the surface on which it is supported. Proper structural support must also be provided during heat treatment operations. When adhesives are used the circuit boards must be cured in a high temperature environment. The circuit board must be properly supported to insure even heating and adequate circulation of air around the board.